The blue spruce, green spruce,[2]white spruce,[3]Colorado spruce, or Colorado blue spruce, with the Latin (scientific) name Picea pungens, is a species of spruce tree. It is native to Canada and the United States, and is found in growing zones 1 through 7[4]. Its natural range extends from northern New Mexico through Colorado and Utah to Wyoming and into Alberta and British Columbia, but it has been widely introduced elsewhere and is used as an ornamental tree in many places far beyond its native range, the blue spruce has blue coloured needles and is a coniferous tree.

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In the wild, Picea pungens grows to about 23 m (75 ft), but when planted in parks and gardens it seldom exceeds 15 m (49 ft) tall by 5 m (16 ft) wide. It is a columnar or conical evergreenconifer with densely growing horizontal branches, it has scaly grey bark on the trunk with yellowish-brown branches.

Waxy gray-green leaves, up to 3 cm (1 in) long, are arranged radially on the shoots which curve upwards. The pale brown cones are up to 10 cm (4 in) long.[5][6][7][8]

The blue spruce is attacked by two species of Adelges, an aphid-like insect that causes galls to form. Nymphs of the pineapple gall adelgid form galls at the base of twigs which resemble miniature pineapples and those of the Cooley's spruce gall adelgid cause cone-shaped galls at the tips of branches. The larva of the spruce budworm eat the buds and growing shoots while the spruce needle miner hollows out the needles and makes them coalesce in a webbed mass. An elongated white scale insect, the pine needle scale feeds on the needles causing fluffy white patches on the twigs and aphids also suck sap from the needles and may cause them to fall and possibly dieback. Mites can also infest the blue spruce, especially in a dry summer, causing yellowing of the oldest needles.[12][13] Another insect pest is the spruce beetle (Dendroctonus rufipennis) which bores under the bark, it often first attacks trees which have blown over by the wind and when the larvae mature two years afterwards, a major outbreak occurs and vast numbers of beetles attack nearby standing trees.[14]

The blue spruce is susceptible to several needle casting diseases which cause the needles to turn yellow, mottled or brown before they fall off. Various rust diseases also affect the tree causing yellowing of the needles as well as needle fall. Canker caused by Cytospora attacks one of the lower branches first and progressively makes its way higher up the tree. The first symptom is the needles turning reddish-brown and falling off. Meanwhile, patches of white resin appear on the bark and the branch eventually dies.[12]

Blue spruce seedlings are shallow roots that penetrate only 6.4 cm (2.5 inches) of soil during the first year.[15] Although freezing can’t damage much in blue spruce, frost will cause seedling loss. Shadows in late spring and early autumn minimize this frost heaving loss,[16][17] despite the shallow roots, blue spruce is able to resist strong winds.[18] Five years before transplanting, the total root surface area of 2-meter-high trees was doubled by pruning the roots of blue spruce, it also increases the root concentration in drip irrigation pipeline from 40% to 60%, which is an advantage in landscape greening.[19]

The Navajo and Keres Native Americans used this tree as a traditional medicinal plant and a ceremonial item, and twigs are given as gifts to bring good fortune. In traditional medicine, an infusion of the needles is used to treat colds and settle the stomach, this liquid is also used externally for rheumatic pains. Early people used their wood for building.[31]

Blue spruce usually grows in cool and humid climatic zones where the annual precipitation is mainly occurred in summer.[37]

Blue spruce is most common in Colorado and the Southwest, the annual average temperature ranges from 3.9 to 6.1 degrees C (39 to 43 degrees F). And ranges from - 3.9 to - 2.8 degrees C (25 to 27 degrees F) in January. In July, the average temperature ranges from 13.9 to 15.0 degrees C (57 to 59 degrees F). The average minimum temperature in January ranges from - 11.1 to 8.9 degrees C (12 to 16 degrees F), and the average maximum temperature in July ranges from 21.1 to 22.2 C (70 to 72 degrees F). There is a frost-free period of about 55 to 60 days from June to August.[38][39]

Annual mean precipitation generally vary from 460 to 610 mm (18 to 24 in). Winter is the season with the poorest rainfall, the precipitation is usually less than 20 percent of the annual moisture falling from December to March. And fifth percent of the annual precipitation occurs during the growing season of the plants.[40][41]

Blue spruce is generally considered to grow best with abundant moisture, nevertheless, this species can withstand drought better than any other spruce,[42] it can withstand extremely low temperatures (-40 degrees C) as well. Furthermore, this species is more resistant to high insolation and frost damage compared to other associated species.[43]

1.
Taxonomy (biology)
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Taxonomy is the science of defining groups of biological organisms on the basis of shared characteristics and giving names to those groups. The exact definition of taxonomy varies from source to source, but the core of the remains, the conception, naming. There is some disagreement as to whether biological nomenclature is considered a part of taxonomy, the broadest meaning of taxonomy is used here. The word taxonomy was introduced in 1813 by Candolle, in his Théorie élémentaire de la botanique, the term alpha taxonomy is primarily used today to refer to the discipline of finding, describing, and naming taxa, particularly species. In earlier literature, the term had a different meaning, referring to morphological taxonomy, ideals can, it may be said, never be completely realized. They have, however, a value of acting as permanent stimulants. Some of us please ourselves by thinking we are now groping in a beta taxonomy, turrill thus explicitly excludes from alpha taxonomy various areas of study that he includes within taxonomy as a whole, such as ecology, physiology, genetics, and cytology. He further excludes phylogenetic reconstruction from alpha taxonomy, thus, Ernst Mayr in 1968 defined beta taxonomy as the classification of ranks higher than species. This activity is what the term denotes, it is also referred to as beta taxonomy. How species should be defined in a group of organisms gives rise to practical and theoretical problems that are referred to as the species problem. The scientific work of deciding how to define species has been called microtaxonomy, by extension, macrotaxonomy is the study of groups at higher taxonomic ranks, from subgenus and above only, than species. While some descriptions of taxonomic history attempt to date taxonomy to ancient civilizations, earlier works were primarily descriptive, and focused on plants that were useful in agriculture or medicine. There are a number of stages in scientific thinking. Early taxonomy was based on criteria, the so-called artificial systems. Later came systems based on a complete consideration of the characteristics of taxa, referred to as natural systems, such as those of de Jussieu, de Candolle and Bentham. The publication of Charles Darwins Origin of Species led to new ways of thinking about classification based on evolutionary relationships and this was the concept of phyletic systems, from 1883 onwards. This approach was typified by those of Eichler and Engler, the advent of molecular genetics and statistical methodology allowed the creation of the modern era of phylogenetic systems based on cladistics, rather than morphology alone. Taxonomy has been called the worlds oldest profession, and naming and classifying our surroundings has likely been taking place as long as mankind has been able to communicate

2.
Plant
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Plants are mainly multicellular, predominantly photosynthetic eukaryotes of the kingdom Plantae. The term is generally limited to the green plants, which form an unranked clade Viridiplantae. This includes the plants, conifers and other gymnosperms, ferns, clubmosses, hornworts, liverworts, mosses and the green algae. Green plants have cell walls containing cellulose and obtain most of their energy from sunlight via photosynthesis by primary chloroplasts and their chloroplasts contain chlorophylls a and b, which gives them their green color. Some plants are parasitic and have lost the ability to produce amounts of chlorophyll or to photosynthesize. Plants are characterized by sexual reproduction and alternation of generations, although reproduction is also common. There are about 300–315 thousand species of plants, of which the great majority, green plants provide most of the worlds molecular oxygen and are the basis of most of Earths ecologies, especially on land. Plants that produce grains, fruits and vegetables form humankinds basic foodstuffs, Plants play many roles in culture. They are used as ornaments and, until recently and in variety, they have served as the source of most medicines. The scientific study of plants is known as botany, a branch of biology, Plants are one of the two groups into which all living things were traditionally divided, the other is animals. The division goes back at least as far as Aristotle, who distinguished between plants, which generally do not move, and animals, which often are mobile to catch their food. Much later, when Linnaeus created the basis of the system of scientific classification. Since then, it has become clear that the plant kingdom as originally defined included several unrelated groups, however, these organisms are still often considered plants, particularly in popular contexts. When the name Plantae or plant is applied to a group of organisms or taxon. The evolutionary history of plants is not yet settled. Those which have been called plants are in bold, the way in which the groups of green algae are combined and named varies considerably between authors. Algae comprise several different groups of organisms which produce energy through photosynthesis, most conspicuous among the algae are the seaweeds, multicellular algae that may roughly resemble land plants, but are classified among the brown, red and green algae. Each of these groups also includes various microscopic and single-celled organisms

3.
Pinophyta
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The Pinophyta, also known as Coniferophyta or Coniferae, or commonly as conifers, are a division of vascular land plants containing a single class, Pinopsida. They are gymnosperms, cone-bearing seed plants, all extant conifers are perennial woody plants with secondary growth. The great majority are trees, though a few are shrubs, examples include cedars, Douglas firs, cypresses, firs, junipers, kauri, larches, pines, hemlocks, redwoods, spruces, and yews. As of 1998, the division Pinophyta was estimated to contain eight families,68 genera, although the total number of species is relatively small, conifers are ecologically important. They are the dominant plants over large areas of land, most notably the taiga of the Northern Hemisphere, boreal conifers have many wintertime adaptations. The narrow conical shape of northern conifers, and their downward-drooping limbs, many of them seasonally alter their biochemistry to make them more resistant to freezing. While tropical rainforests have more biodiversity and turnover, the conifer forests of the world represent the largest terrestrial carbon sink. Conifers are of economic value for softwood lumber and paper production. The earliest conifers in the record date to the late Carboniferous period, possibly arising from Cordaites. Pinophytes, Cycadophytes, and Ginkgophytes all developed at this time, an important adaptation of these gymnosperms was allowing plants to live without being so dependent on water. Other adaptations are pollen and the seed, which allows the embryo to be transported and developed elsewhere, Conifers appear to be one of the taxa that benefited from the Permian–Triassic extinction event, and were the dominant land plants of the Mesozoic. They were overtaken by the plants, which first appeared in the Cretaceous. They were the food of herbivorous dinosaurs, and their resins and poisons would have given protection against herbivores. Reproductive features of modern conifers had evolved by the end of the Mesozoic era, Conifer is a Latin word, a compound of conus and ferre, meaning the one that bears cone. A descriptive name in use for the conifers is Coniferae. Alternatively, descriptive botanical names may also be used at any rank above family and this means that if conifers are considered a division, they may be called Pinophyta or Coniferae. As a class they may be called Pinopsida or Coniferae, as an order they may be called Pinales or Coniferae or Coniferales. Conifers are the largest and economically most important component group of the gymnosperms, the division Pinophyta consists of just one class, Pinopsida, which includes both living and fossil taxa

4.
Spruce
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A spruce is a tree of the genus Picea /paɪˈsiːə/, a genus of about 35 species of coniferous evergreen trees in the family Pinaceae, found in the northern temperate and boreal regions of the earth. Spruces are large trees, from about 20–60 m tall when mature, the needles, or leaves, of spruce trees are attached singly to the branches in a spiral fashion, each needle on a small, peg-like structure. The needles are shed when 4–10 years old, leaving the branches rough with the retained pegs, spruces are used as food plants by the larvae of some Lepidoptera species. They are also used by the larvae of gall adelgids, the word spruce entered the English language from the Polish Prusy, Prussia. DNA analyses have shown that traditional classifications based on the morphology of needle, Spruce has been found in the fossil record from the early Cretaceous,136 million years ago. Thirty-five named species of spruce exist in the world, the Plant List has 59 accepted spruce names. Beyond that, determination can become more difficult, intensive sampling in the Smithers/Hazelton/Houston area of British Columbia showed Douglas, according to Coates et al. Daubenmire, after sampling, had already recognized the importance of the 2 latter characters. Without cones, morphological differentiation among spruce species and their hybrids is more difficult, but, if an extended photoperiod is provided for Sitka spruce, seedlings become unacceptably tall by the end of the first growing season. g. Growth rhythm, shoot and root weight, and needle serration, or some combination of, Spruce seedlings are most susceptible immediately following germination, and remain highly susceptible through to the following spring. Seedlings that germinate late in the season are particularly vulnerable because they are tiny and have not had time to harden off fully. Mortality rates generally decrease sharply thereafter, but losses often remain high for some years, establishment is a subjective concept based on the idea that once a seedling has successfully reached a certain size, not much is likely to prevent its further development. Growth remains very slow for several to many years, Spruce is useful as a building wood, commonly referred to by several different names including North American timber, SPF and whitewood. Spruce wood is used for many purposes, ranging from construction work. The Wright brothers first aircraft, the Flyer, was built of spruce, because this species has no insect or decay resistance qualities after logging, it is generally recommended for construction purposes as indoor use only. Spruce wood, when left outside cannot be expected to last more than 12–18 months depending on the type of climate it is exposed to, Spruce is one of the most important woods for paper uses, as it has long wood fibres which bind together to make strong paper. The fibres are thin walled and collapse to thin bands upon drying, spruces are commonly used in mechanical pulping as they are easily bleached. Together with northern pines, northern spruces are commonly used to make NBSK, spruces are cultivated over vast areas as pulpwood

5.
Species
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In biology, a species is the basic unit of biological classification and a taxonomic rank. A species is defined as the largest group of organisms in which two individuals can produce fertile offspring, typically by sexual reproduction. While this definition is often adequate, looked at more closely it is problematic, for example, with hybridisation, in a species complex of hundreds of similar microspecies, or in a ring species, the boundaries between closely related species become unclear. Other ways of defining species include similarity of DNA, morphology, all species are given a two-part name, a binomial. The first part of a binomial is the genus to which the species belongs, the second part is called the specific name or the specific epithet. For example, Boa constrictor is one of four species of the Boa genus, Species were seen from the time of Aristotle until the 18th century as fixed kinds that could be arranged in a hierarchy, the great chain of being. In the 19th century, biologists grasped that species could evolve given sufficient time, Charles Darwins 1859 book The Origin of Species explained how species could arise by natural selection. Genes can sometimes be exchanged between species by horizontal transfer, and species may become extinct for a variety of reasons. In his biology, Aristotle used the term γένος to mean a kind, such as a bird or fish, a kind was distinguished by its attributes, for instance, a bird has feathers, a beak, wings, a hard-shelled egg, and warm blood. A form was distinguished by being shared by all its members, Aristotle believed all kinds and forms to be distinct and unchanging. His approach remained influential until the Renaissance, when observers in the Early Modern period began to develop systems of organization for living things, they placed each kind of animal or plant into a context. Many of these early delineation schemes would now be considered whimsical, animals likewise that differ specifically preserve their distinct species permanently, one species never springs from the seed of another nor vice versa. In the 18th century, the Swedish scientist Carl Linnaeus classified organisms according to shared physical characteristics and he established the idea of a taxonomic hierarchy of classification based upon observable characteristics and intended to reflect natural relationships. At the time, however, it was widely believed that there was no organic connection between species, no matter how similar they appeared. However, whether or not it was supposed to be fixed, by the 19th century, naturalists understood that species could change form over time, and that the history of the planet provided enough time for major changes. Jean-Baptiste Lamarck, in his 1809 Zoological Philosophy, described the transmutation of species, proposing that a species could change over time, in 1859, Charles Darwin and Alfred Russel Wallace provided a compelling account of evolution and the formation of new species. Darwin argued that it was populations that evolved, not individuals and this required a new definition of species. Darwin concluded that species are what appear to be, ideas

6.
Colorado
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Colorado is a state in the United States encompassing most of the Southern Rocky Mountains as well as the northeastern portion of the Colorado Plateau and the western edge of the Great Plains. Colorado is part of the Western United States, the Southwestern United States, Colorado is the 8th most extensive and the 21st most populous of the 50 United States. The United States Census Bureau estimates that the population of Colorado was 5,540,545 on July 1,2016, the state was named for the Colorado River, which Spanish travelers named the Río Colorado for the ruddy silt the river carried from the mountains. The Territory of Colorado was organized on February 28,1861, Colorado is nicknamed the Centennial State because it became a state in the same year as the centennial of the United States Declaration of Independence. Colorado is noted for its landscape of mountains, forests, high plains, mesas, canyons, plateaus, rivers. Denver is the capital and the most populous city of Colorado, residents of the state are properly known as Coloradans, although the term Coloradoan has been used archaically and lives on in the title of Fort Collins newspaper, the Coloradoan. Colorado, Wyoming and Utah are the states which have boundaries defined solely by lines of latitude and longitude. The summit of Mount Elbert at 14,440 feet elevation in Lake County is the highest point in Colorado, Colorado is the only U. S. state that lies entirely above 1,000 meters elevation. The point where the Arikaree River flows out of Yuma County, Colorado and this point, which holds the distinction of being the highest low elevation point of any state, is higher than the high elevation points of 18 states and the District of Columbia. A little less than one half of the area of Colorado is flat, East of the Rocky Mountains are the Colorado Eastern Plains of the High Plains, the section of the Great Plains within Nebraska at elevations ranging from roughly 3,350 to 7,500 feet. The Colorado plains were mostly prairies, but they have many patches of forests, buttes. Eastern Colorado is presently covered in farmland and rangeland, along with small farming villages. Precipitation is fair, averaging from 15 to 25 inches annually, corn, wheat, hay, soybeans, and oats are all typical crops, and most of the villages and towns in this region boast both a water tower and a grain elevator. Irrigation water is available from the South Platte, the Arkansas River, and a few other streams, however, heavy use of ground water from wells for irrigation has caused underground water reserves to decline. As well as agriculture, eastern Colorado hosts considerable livestock, such as cattle ranches. Roughly 70% of Colorados population resides along the edge of the Rocky Mountains in the Front Range Urban Corridor between Cheyenne, Wyoming, and Pueblo, Colorado. This region is protected from prevailing storms that blow in from the Pacific Ocean region by the high Rockies in the middle of Colorado. The Front Range includes Denver, Boulder, Fort Collins, Loveland, Colorado Springs, Pueblo, Greeley and other townships, on the other side of the Rockies, the significant population centers in Western Colorado are the cities of Grand Junction, Durango, and Montrose

7.
Cultivar
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The term cultivar most commonly refers to an assemblage of plants selected for desirable characteristics that are maintained during propagation. More generally, cultivar refers to the most basic classification category of cultivated plants governed by the ICNCP, most cultivars have arisen in cultivation, but a few are special selections from the wild. Popular ornamental garden plants like roses, camellias, daffodils, rhododendrons, trees used in forestry are also special selections grown for their enhanced quality and yield of timber. Cultivars form a part of Liberty Hyde Baileys broader grouping. Cultivar was coined by Bailey and it is regarded as a portmanteau of cultivated and variety. A cultivar is not the same as a variety, a taxonomic rank below subspecies. In recent times, the naming of cultivars has been complicated by the use of statutory plant patents, the International Union for the Protection of New Varieties of Plants offers legal protection of plant cultivars to people or organisations who introduce new cultivars to commerce. UPOV requires that a cultivar be distinct, uniform and stable, to be distinct, it must have characteristics that easily distinguish it from any other known cultivar. To be uniform and stable, the cultivar must retain these characteristics under repeated propagation, a cultivar is given a cultivar name, which consists of the scientific Latin botanical name followed by a cultivar epithet. The cultivar epithet is usually in a vernacular language, for example, the full cultivar name of the King Edward potato is Solanum tuberosum King Edward. The King Edward part of the name is the cultivar epithet, the origin of the term cultivar arises from the need to distinguish between wild plants and those with characteristics that have arisen in cultivation. This distinction dates back to the Greek philosopher Theophrastus, the Father of Botany, botanical historian Alan Morton notes that Theophrastus in his Enquiry into Plants had an inkling of the limits of culturally induced changes and of the importance of genetic constitution. In Species Plantarum, Linnaeus listed all the known to him. Most of the listed by Linnaeus were of garden origin rather than being wild plants. Over time there was an increasing need to distinguish between plants growing in the wild, and those with variations that had produced in cultivation. In the nineteenth century many garden-derived plants were given names, sometimes in Latin. In the twentieth century an improved international terminology was proposed for the classification and it is essentially the equivalent of the botanical variety except in respect to its origin. However, Bailey was never explicit about the etymology of the word, and it has suggested that it is a contraction of the words cultigen and variety

8.
Christmas tree
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A Christmas tree is a decorated tree, usually an evergreen conifer such as spruce, pine, or fir or an artificial tree of similar appearance, associated with the celebration of Christmas. The modern Christmas tree was developed in early modern Germany, in which devout Christians brought decorated trees into their homes and it acquired popularity beyond the Lutheran areas of Germany, during the second half of the 19th century, at first among the upper classes. The tree was decorated with roses made of colored paper, apples, wafers, tinsel. In the 18th century, it began to be illuminated by candles which were replaced by Christmas lights after the advent of electrification. Today, there is a variety of traditional ornaments, such as garlands, baubles, tinsel. An angel or star might be placed at the top of the tree to represent the archangel Gabriel or the Star of Bethlehem from the Nativity. Edible items such as gingerbread, chocolate and other sweets are also popular, the Christmas tree is sometimes compared with the Yule-tree, especially in discussions of its folkloric origins. The relevance of ancient pre-Christian customs to the 16th Century German initiation of the Christmas tree custom is disputed, resistance to the custom was often because of its confirmed Lutheran origins. Other sources have tried to make a connection between the first documented Christmas trees in Alsace around 1600 and pre-Christian traditions. For example, according to the Encyclopædia Britannica, The use of trees, wreaths, and garlands to symbolize eternal life was a custom of the ancient Egyptians, Chinese. During the Roman mid-winter festival of Saturnalia, houses were decorated with wreaths of evergreen plants, the modern Christmas tree is frequently traced to the symbolism of trees in pre-Christian winter rites, wherein Viking and Saxon worshiped trees. The story of Saint Boniface cutting down Donars Oak illustrates the pagan practices in 8th century among the Germans. Alternatively, it is identified with the tree of paradise of medieval mystery plays that were given on 24 December, in such plays, a tree decorated with apples and wafers was used as a setting for the play. Like the Christmas crib, the Paradise tree was placed in homes. The apples were replaced by objects such as shiny red balls. Modern Christmas trees originated during the Renaissance of early modern Germany and its 16th-century origins are sometimes associated with Protestant Christian reformer Martin Luther who is said to have first added lighted candles to an evergreen tree. The first recorded Christmas tree can be found on the sculpture of a private home in Turckheim, Alsace. The Georgians have their own traditional Christmas tree called Chichilaki, made from dried up hazelnut or walnut branches that are shaped to form a small coniferous tree and these pale-colored ornaments differ in height from 20 cm to 3 meters

9.
Nymph (biology)
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In biology, a nymph is the immature form of some invertebrates, particularly insects, which undergoes gradual metamorphosis before reaching its adult stage. Unlike a typical larva, an overall form already resembles that of the adult. In addition, while a nymph moults it never enters a pupal stage, instead, the final moult results in an adult insect. Nymphs undergo multiple stages of development called instars and this is the case, for example, in Orthoptera, Hemiptera, mayflies, termites, cockroaches, mantises, stoneflies and Odonata. Nymphs of aquatic insects, as in the Odonata, Ephemeroptera, and Plecoptera, are called naiads. In older literature, these were referred to as the heterometabolous insects, as their adult. In fly fishing with flies, this stage of aquatic insects is the basis for an entire series of representative patterns for trout. They account for half of the over all patterns regularly fished in the United States

10.
Pineapple gall adelgid
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The Pineapple gall adelgid is a type of conifer-feeding insect that forms pineapple-shaped plant galls on its host species, commonly Norway and Sitka spruce. The adelgids are pear-shaped, soft-bodied green insects with long antennae, Adelges lays up to one hundred eggs at a time, one on each needle. Adelges abietis is one of the most common species, synonyms are A. gallarum-abietis, Chermes abietis, prominent in appearance, the pineapple or pseudocone gall is often confused with the actual cone of the tree, due to their superficial resemblance. Pineapple galls are distinguishable by their size, position on the base of budding twigs. The pineapple gall adelgid is endemic to Europe, belonging to the woolly adelgid group, Spruce gall aphid, eastern spruce pineapple gall adelges and eastern spruce gall aphid are alternative names. This insect belongs to the superfamily Aphidoidea, and family Adelgidae and it is the primary pest of Norway Spruce. Another similar species, the Cooley spruce gall adelgid, is indigenous to North America and this adelgid usually affects Colorado Blue, Sitka, Englemann, and Oriental spruces. The eastern spruce gall adelgid is a species that feeds only on spruce. At least in 1985, the species was found in Canada from Ontario eastward, the gall is formed from the swelling of the bases of the needles punctured by the feeding activity and activated by the saliva of the insect. The unilarval chambers are set in a woody core, the stem and needles of the host can continue growing beyond the position of the gall. Sitka and Norway spruce are the hosts, but A. abietis galls can be found on Colorado blue, white. The yellowish green galls pass through pink and then reddish-brown colour phases, on average, they measure 1.5 to 3.0 cm in length. The Cooley spruce gall adelgids form a larger gall,1 to 3 inches long, only females of the pineapple gall adelgid are known. The nymphs overwinter under wax threads at the base of buds and they die shortly afterwards, leaving the eggs, which resemble white, cottony twigs, protected beneath their bodies. In late summer the fully developed nymphs emerge from the galls and crawl out onto the needles and these adult adelgids may fly to other susceptible conifers, such as larch, pine and silver fir or may continue the cycle on the same tree, as some are poor flyers. Several generations are raised on these hosts, however no galls are formed. In July of the following year winged adelgid appear and fly to the spruces to breed there again, some herbivorous insects create their own microhabitats by forming a highly distinctive plant structure called a gall, made up of plant tissue, but controlled by the insect. Galls act as both the habitat, and food sources for the maker of the gall, the interior of a bedeguar gall is formed from the bud, and is composed of edible nutritious and structural tissues

11.
Canker
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Canker and anthracnose generally refer to many different plant diseases of such broadly similar symptoms as the appearance of small areas of dead tissue, which grow slowly, often over years. Some are of minor consequence, but others are ultimately lethal. Their causes include such a range of organisms as fungi, bacteria, mycoplasmas. The majority of canker-causing organisms are bound to a unique host species or genus, weather and animals can spread canker, thereby endangering areas that have only slight amount of canker. Although fungicides or bactericides can treat some cankers, often the only treatment is to destroy the infected plant to contain the disease. Apple canker, caused by the fungus Neonectria galligena Ash bacterial canker, now understood to be caused by the bacterium Pseudomonas savastanoi, after DNA-relatedness studies Pseudomonas savastanoi has been instated as a new species. Butternut canker, caused by the fungus Sirococcus clavigignenti-juglandacearum Bleeding Canker of Horse Chestnut, caused by the bacterium Pseudomonas syringae pv

12.
Resin
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In polymer chemistry and materials science, resin is a solid or highly viscous substance of plant or synthetic origin that is typically convertible into polymers. They are often mixtures of compounds, principally terpenes. Many plants, particularly woody plants, produce resin in response to injury, the resin acts as a bandage protecting the plant from invading insects and pathogens. Plants secrete resins and rosins for their protective benefits, the resin produced by most plants is composed mainly of terpenes and derivatives. Some resins also contain a proportion of resin acids. The individual components of resin can be separated by fractional distillation, rosins on the other hand are less volatile and consist, inter alia, of diterpenes. Amber is fossil resin from coniferous and other tree species, copal, kauri gum, dammar and other resins may also be found as subfossil deposits. Subfossil copal can be distinguished from genuine fossil amber because it becomes tacky when a drop of a solvent such as acetone or chloroform is placed on it, african copal and the kauri gum of New Zealand are also procured in a semi-fossil condition. Solidified resin from which the volatile terpene components have been removed by distillation is known as rosin, typical rosin is a transparent or translucent mass, with a vitreous fracture and a faintly yellow or brown colour, non-odorous or having only a slight turpentine odor and taste. Rosin is insoluble in water, mostly soluble in alcohol, essential oils, ether and hot fatty oils, and softens and melts under the influence of heat, rosin consists of a complex mixture of different substances including organic acids named the resin acids. These are closely related to the terpenes, and derive from them through partial oxidation, Resin acids can be dissolved in alkalis to form resin soaps, from which the purified resin acids are regenerated by treatment with acids. Examples of resin acids are abietic acid, C20H30O2, plicatic acid contained in cedar, and pimaric acid, C20H30O2, a constituent of galipot resin. Abietic acid can also be extracted from rosin by means of hot alcohol, it crystallizes in leaflets, pimaric acid closely resembles abietic acid into which it passes when distilled in a vacuum, it has been supposed to consist of three isomers. Rosin is obtained from pines and some plants, mostly conifers. Propolis, consisting largely of resins collected from such as poplars and conifers, is used by honey bees to seal gaps in their hives. Shellac and lacquer are examples of insect-derived resins, asphaltite and Utah resin are petroleum bitumens, not a product secreted by plants, although it was ultimately derived from plants. These were highly prized substances, and required as incense in religious rites. The word resin has been applied in the world to nearly any component of a liquid that will set into a hard lacquer or enamel-like finish

Bread wheat, Triticum aestivum, is considered a cultigen, and is a distinct species from other wheats according to the biological species concept. Many different cultivars have been created within this cultigen. Many other cultigens are not considered to be distinct species, and can be denominated otherwise.